The firm had already predicted weak demand for the Model 3 in the first quarter of 2019 because of the phaseout of a tax credit that lowered its cost in the US and continued problems with European delivery, but Goldman says the unveiling of the Model Y crossover could make Model 3 demand problems worse.

"While the unveil of the Model Y could drive incremental reservations — given a much larger global market for crossovers than sedans — and help cash balances given likely deposit collection, this new product could further weigh on Model 3 demand as consumers decide to wait a little longer to purchase a Tesla crossover vehicle," Tamberrino wrote.

Citing data from InsideEVs, the note detailed Tesla has already experienced a sequential sales declines of 66% for the Model 3 during the first two months of 2019.

Goldman Sachs

Given that Tamberrino estimates the Model Y will drive between 200,000 to 400,000 orders given the preference for crossovers over sedans in the US, this could serve as another factor in weakening Model 3 demand given the similar price point for the two vehicles. Tesla CEO Elon Musk said the Model Y would be priced about 10% higher than the Model 3.

A further drop in Model 3 demand would be an unwelcome sign for investors, who were previously looking at the $35,000 vehicle to drive significant demand. Customers had placed 450,000 deposits for the car well ahead of its launch, starting in 2016.

However, that demand appears to have been at least partially driven by the US federal tax credit for electric vehicles. Goldman noted the price after the $7,500 credit would have been comparable to a well-appointed Toyota Camry.

Demand now appears to be flagging with many of those deposits refunded as the tax credit is now being phased out. Many customers have also became frustrated with the extended wait for the $35,000 Model 3, canceling their orders. Currently, there is no backlog for Model 3 delivery in the US, with an estimated delivery time for the $35,000 vehicle ranging from six to eight weeks, according to Tesla's website.

And while Goldman says the February 28 announcement of a $35,000 Model 3 may drive incremental demand in the US, the firm predicted such orders would cause a drop in gross margins, from 19% in 2018 to 18% in 2019.